1. Field of the Invention
The present invention relates to a scanning apparatus for a scanning microscope, and particularly relates to a lens scanning apparatus for an ultrasonic microscope.
2. Related Art Statement
In recent years, an ultrasonic microscope has been put to practical use in which a sample to be observed is two-dimensionally scanned with an ultrasonic beam and reflected waves or transmitted waves from the sample are received to form an ultrasonic image of the sample. In the ultrasonic microscope, a sample should be scanned through relatively two-dimensional moving a lens and a sample. As such a scanning method, there are various methods including a method of scanning a lens in the X direction and scanning a sample in the Y direction, a method of scanning a lens and a sample in the X-Y direction and so on. Also, although there are various means for scanning a lens or a sample in the X-Y direction, one of such means is the X-Y scanner used for a low temperature ultrasonic microscope, shown on pages 17 and 18 in Acoustical Imaging, Vol. 12.
In this X-Y scanner, for example, a lens supporting stand for supporting a lens is fitted to a scanner supporting stand through a spring(tube). A coil is fitted to this lens supporting stand, but on the other hand, a magnet is fitted to the scanner supporting stand. By these coil and magnet, the lens supporting stand can be moved in the X-Y direction.
The above mentioned scanner has superior features in several points, but on the other hand, if the above mentioned spring is made to be inelastic so as to be able to drive the electric power as small as possible, the scanner is easily vibrated by a variation coming from the outside, by noise of a driving signal, by relative harmonic contents and so on. Such a variation becomes a deflection of the picture image and will remarkably reduces the quality of a picture. Therefore, an electrical counterplan such as a servomechanism, has been usually considered; however, the counterplan is not enough, especially for above mentioned several noises of a frequency near the resonance point.